1. Field of the Invention
The present invention relates to a musical tone signal generating apparatus for generating synthesized musical tone signals, and more particularly to a musical tone signal generating apparatus provided with a plurality of voice units for independently synthesizing musical tone signals applied thereto.
2. Description of the Prior Art
Disclosed in Japanese Utility Model Publication No. 62-20878 is a musical tone signal generating apparatus of the type which includes a plurality of voice units connected to a common data bus to synthesize musical tone signals of different fixed tone colors. In the musical tone generating apparatus, the voice units are applied with a selection data together with a tone pitch data and a tone volume data from the common data bus to synthesize the musical tone signals of fixed tone colors in a condition where the tone color of the synthesized musical tone signal is identical with a tone color defined by the selection data.
In such a conventional musical tone signal generating apparatus as described, an additional voice unit of a fixed tone color can be connected to the common data bus to produce musical tone signals of various tone colors. However, each tone color of the musical tone signals produced by the voice units is fixed. For this reason, it is required to provide various kinds of voice units for producing musical tone signals of various tone colors.